Electric-arc lamp.



No.'667,|2|. Patented m. 29, I90l. n. FLEMING.

ELECTRIC ABC LAMP.

(Application filed Mar. 2, 1899.)

3 ShoutsSheet I.

(No Model.)

FIE-1- B4- B5 INVEH EJ Richard Fleming,

b J b'by.

\A/ITIJESSES. A. H-Mw mt. Noam: PETERS No. 667,l2l. Patented Jan; 29, |9o|.'

I n. FLEMING.

ELECTRIC 'ARC LAMP.

(Appliution' mad In; 2, 1899.

(No Model.) 3 Sheets-Shoat 2.

IH/EN UR. Richard Ffieming no. ss7,|2|. Patented l'an. 29,190l.

n. FLEMING.

ELECTRIC A'BC LAMP.

(Application Blad m. a, 1590.)

3 Sheats-Sheet 3.

(No Model.)

I i m m a TI INIM .fl WM a s M x 66 My W J w x M A WV WI E 1N UNITED STATES PATENT OFFICE.

RICI-IARD FLEMING, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE GENERAL y ELECTRIC COMPANY, OF NEIV YORK. I

ELECTRIC-ARC LAMP.

SPECIFICATION formingpart of Letters Patent No. 667,121, dated January 29, 1901.

Application filed March 2, 1899. Serial No. 707,424. (No model.)

In no whom it may concern:

Be it known that I, RICHARD FLEMING, a subject of the Queen of Great Britain, residing at Lynn, in the county of Essex and State of lvlzissachusetts, have invented certain new and useful Improvemen ts in Arc-Lam ps, (Case No. 888,) of which the following is a specification.

The present invention relates to electricarc lamps, and more particularly to alternating-current lamps designed for use on coustant-curreut series circuits, although certain of the features of novelty are applicable to other types of lamps.

My invention has for its object to improve the construction of electric-arc lamps; and to that end it consists in the parts and combinations of parts, as hereinafter more fully described and claimed.

In the accompanying drawings, which show an embodiment of my invention, Figure 1 is a side elevation of a lamp with the outer casing and outer globe removed. Fig. 2 is a section taken on line 2 2 of Fig. 1. Fig. 3 is a longitudinal section of the actuating-magnets, taken on line 3 3 of Fig. 1. Fig. 4 is a diagram. Fig. 5 is a detail of the frame construction, and Figs. 6 and 7 are detail views of a spring-supported reactance. I

Referring first to Fig. 1, A is a cast-metal U-shaped piece forming the upper part of the frame, and extending downwardly therefrom are two side tubes B. These tubes are secured in place by extending the upper end of the tube into the projection A of the frame. Connecting the lower ends of the tube is a yoke 13, which supports the lowercarbon holder B and the inner-globe holder B Mounted for vertical movement within the tubes are rods 13, which carry the outerglobe holder B Mounted on the tubes in such manner that they may be moved up and down for the purposes of assembling or repairing the lamp are two heads C and C. These heads are separated by an air-space on the outer edge and are connected in the center by a hub C The air-space between the heads is to prevent the heat from the arc from rising upward and aifecting the operation of the lamp. Screw-threaded or otherwise secured to the upper head C are four vertically-extending rods D. These rods are arranged in pairs, the members of which stand parallel to each other and form supports for the series magnets E and the sh untmagnets F. In assembling the lamp the rods D are first screwed into the head C, the heads are then mounted on the tubes, after which the magnets are slipped over the rods and the whole secured to casting A by screws D, as shown in Fig. 5. This is a very desirable arrangement, since it permits the lamp parts to be readily assembled during the process of manufacture, and it also permits the lamp to be taken down for the purpose of repairs with very little labor. After the screws D are in place the heads 0 and C are retained in the position shown, and no other support is required.

The heads of the magnets E and F are provided with projections at, having holes therein for receiving the rods D. These heads serve to support the magnets and keep them in proper alinement. Between the upper head of the lower or shunt magnet F and the lower head of the series magnet E are separators H. There are four of these separators, one for each of the rods D. This arrangement serves to hold the magnets E and F at the proper distance apart.

Secured by screws to the under side of the frame Ais a rectangular laminated armature I. This armature is separated from the upper spool-head of the magnet E by a slight space, separators or collars H being employed to hold the upper magnets in place. In the present instance I have shown four magnets-two included in the series circuit and two in the shunt-circuit. In certain instances'I may omit the series magnets and substitute therefor a spring or springs. This construction admits of shortening the lamp considerably. I still, however, preserve the same arrangement of parts-that is to say, the shunt-magnet F and the heads C and C 95 are supported by the rods D in the same manner as before.

Heretofore great difficulty has been experienced in making a satisfactory arc-lamp to Work on constant-current alternating circuits, IO 2 the chief difficulty being to geta shunt-mag net which had a substantially constant pull over a wide range of movement. In the present invention I overcome this difficulty by the peculiar construction and arrangement of the moving core and the stationary armature.

Referring to Fig. 3,the construction of the core and its armature will be plainly seen. Screwed to the frame-casting A is a laminated iron core I, which is rectangular in outline. This forms the armature for completing the circuit of the upper portion of the core Q. The armature for the shunt-magnet F differs from that of the series magnet E by reason of the projections which extend upward into the coil. I have found that in certain types of lamps if these projections extend about onethird of the way into the coils a magnet of substantially constant pull is obtained; but I do not limit myself to the proportions shown, since changes in the winding necessitate changes in the core and armature.

In arc-lamps designed for direct-current use no particular inconvenience is experienced in making magnets which will have a substantially constant pull over a wide range. This is due to the fact that the resistance of the winding is practically the only thing to be considered, whereas in a magnet designed for alternating-current work the reactance has to be considered, as well as the resistance of the winding. In other words, when the position of the core is changed in an alternating-current magnet the effect of that magnet on the circuit is changed. It is well known that an iron core moving into and out of a solenoid-magnet which is energized by an alternating current will vary the amount of current passing through said magnet, the flow of current in a given instance being least when the core is inserted to its fullest extent and greatest when the core is withdrawn to its limit. It is also well known that a pull between two magnetized pieces of iron or other material is greatest when the parts are in close proximity and that as they are separated the attraction between them diminishes very rapidly.

In constructing the magnets of my lamp I make use of two well-known laws above referred to, and by properly proportioning the parts I have produced a magnet which is so constructed that as the core Q moves into the magnet-coils and the magnetic pull between the core and the armature increases the current [lowing in the coil (and consequently the attractive effect of the coil and armature) is correspondingly decreased. Thus the sum of the two forces remains practically constant, and consequentlythe pullof the core. Ihave shown this arrangement applied only to the shunt-winding, as it has its greatest utility in this connection; but, if desired, it can be applied to the series magnets.

Extending upward through the center of the lamp is a carbon-tube J. This tube is guided at the top and bottom by detachable guides J and J On the lower end of the tube is mounted aclutch J of any suitable pattern, the one shown comprising a collar and two arms which are arranged to grasp the upper carbon K between them when the tube is raised and release the carbon when the tube is lowered. Secured to the tube at any suitable point is a collar J, and connected to this collar is a flexible cable .I 'forconveying current to or from the tube J. Secured to the carbon-tube at a point midway of its length is a support L, and secured to the support, but insulated therefrom by insulating material I), is a right-angle piece L, to which the dash-pot M is connected. Mounted for movement within the magnets E and F is the H-shaped core Q. This core is connected to the support L by a flat spring-plate N and a coil-spring N. The latter is mounted on the upwardly-extending portion of the L-shaped support L. To the upwardly-extending portion of the spring-plate N is connected an extension-spring O, the upper end of which is secured to the frame A by a suitable adjusting means. This extension-spring is designed to compensate to a certain degree for the weight of the moving core. The spring-plate N has a central hole to permit the carbon-tube to pass through it, and extending doumwardly from one end is a projection N", to which is secured the core Q. The arrangement ot'the spring for supporting the core is a very desirable one, since it reduces the vibration between the parts of the lamp and also the noise to a minimum and at the same time forms a very simple construction. The cylinderof the dashpot M, which dash-pot is employed to check the too-rapid movements of the core, is se' cured to the moving support L, and the piston is supported by a clamp M, which is socured to the side tube B.

Mounted on the H-shaped core Q, but i11- sulated therefrom, is a contact R, which ongages with a contact R when the core settles to its lowest position. The contact R is mounted in such a manner that it can be adjusted vertically on the tube B. These contacts form a mechanical cut-out for the lamp that is to say, the contacts will engage whenever the core drops to its lowest point-and also an electromagnetic cut-out, since when the resistance of the arc increases to an abnormal amount the current flowing through the shunt-winding F will be sufficient to overpower the ettect of the series winding E and pull the core downward, so that the contacts will be in engagement with each other. Situated in the right-hand side of the lamp and mounted on a suitable insulating-s11pport is a resistance P, the action of which will be described hereinafter.

Referring to Fig. t, the circuit connection will be described. The current enters atone bindingpost-as T, for exampleflows through the wire t and resistance P, thence to the binding-post T. A second circuit is from binding-post T through the series winding E to the upper and lower carbon, thence IIS to binding-post T, the resistance being so arranged that a certain amount of current is diverted through this winding. A third circuit is from the binding-post T through the coils of the shunt-magnet F to the bindingpost T. The lamp shown is differentially wound and operates in the ordinary manner now well understood.

Referring to Figs. 6 and 7, I have shown a reactance such as is employed when the lamp is used on alternating-current constant-potential circuits. The reactance is mounted under the cover of the lamp and is so arranged that the carbon-carrier J is free to move within the central opening S This reactance comprises a bundle of laminae S, each lamina being circular in outline and pro vided with an air-gap s in the magnetic circuit. No particular means are shown for holding the laminae together; but it is to be understood that any of the well-known means may be employed. Mounted on the core and connected in series with the lamp in the ordinary manner is a suitable insulated wind ing S.

To avoid the humming due to the vibration of the reactance, a spring-support is provided, consisting of three screws S each screw being mounted in the lamp-frame A and surrounded by a coilspring S upon which the core rest-s. In mounting the core of the lamp it is preferable to place a screw ot' non-magnetic material on each side of the air-gap s and to place the third screw about opposite the air -gap. By arranging the screws in this manner they do not interfere with the winding of the core, since the winding may readily be divided into two sections and the screw located between the sections. The arrangement above described permits the reactance to move freely in a vertical direction, but at the same time prevents it from twisting out of line, and the springs act as cushions to reduce the vibration and humming. Besides this the distributed position of the spring-supports affords free access of air to the reactance and prevents undue heating. It is to be understood that when I use the lamp on constant-potential circuits some slight changes are desirable-as, for example, omitting the cut-out.

I am aware that itis not new in direct-current lamps to have magnets which will give a constant pull over a wide range of movement; but in so far as I am aware I am the first to provide in an alternating'current electric-arc lamp a shunt-magnet having a substantially constant pull over a wide range of movement. It is essential in arc-lamps of the inclosed type that the core shall have an extended movement, since it is necessary for the successful operation of inclosed -arc lamps to draw a long arc-as to 1}, for exampleand to do this it is either necessary to have a very powerful magnet and to multiply the movement of its armature by suitable levers or else employ a magnet havinga core adapted to work over a wide range. The latter is by far preferable, and by the arrangement shown in the drawings Iain enabled to provide a very simple lamp, yet one capable of perfect regulation.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In an alternating-current arc-lamp, the combination of a solenoid-actuating magnet, a fixed core, and an armature which extends into the solenoid; the armature, core and solenoid being so arranged that as the space between the armature and the core decreases, the reactance, introduced into the circuit of the solenoid by the armature, is sufliciently increased to offset the effect of the decreased separation of the armature and core so that a substantially even pull on the armature is obtained, and this over a wide range of movement.

2. In an alternatirig-current arc-lamp, the combination of a solenoid-magnet, an armature which enters and moves within the solenoid; the magnetic centers of the solenoid and the armature being so arranged that they never coincide, and a core, the said solenoid, armature and core being so arranged that as the air-gap between the armature and the core decreasesthe impedance to the passage of current in the solenoid increases in such proportion as to li mit the current to an amount which will give a si'ibstantially constant pull on the armature over its entire range of movement.

In an alternating-current arc-lamp, the combination of the shunt-wound operatingmagnet having a fixed and a moving core, the fixed and moving core both extending within the coil, the arrangement of the magnetic material in the cores being such that as they assume a position where the magnetic attraction would normally be greater the currentflow in the coil is decreased, so that the pull is maintained substantially constant at all times.

4. In an electric-arc lamp, the combination .of an upper frame-piece, a side tube or rod in such a manner that it can be moved up and down, and a pair of parallel rods which are screwed to the head and the frame for holding the parts, and arc-regulating mechanism supported by the head and rods.

6. In an arc-lamp, the combination of a frame, a pair of side tubes depending from the frame, a head mounted on the side tubes &

and adapted to be moved thereon, a pair of parallel rods which are secured to the head of the frame for holding the parts in fixed relation, and magnets mounted on the parallel rods and held in place thereby.

7. In an arc-lamp, the combination of a clutch-carrier, a ll] agnet-core secured thereto, adepending side tube forming a part of the lamp-frame,a dash-pot for checking the move ments of the core and an adjustable clamp secured to the side tube by which the stationary element of the dash-pot is supported.

8. In an electric-arclamp, the combination of a magnet, a moving core therefor, a clutchcarrier, a spring-plate secured to the core through which the carrier extends and a spring which is secured to the plate and assists in sustaining the weight of the core and also that of the clutch-carrier.

9. In an electric-arc lamp, the combination of a magnet, a core therefor, a clutch-carrier, a spring-plate secured to the core through which the carrier extends, a clamp carried by the carrier and a spring connection between the clamp and the spring-plate.

10. In an electric-arc lamp, the combination of a frame-piece, a pair of side rods rigidly secured thereto, a head having openings therein th rough which the rods freely pass, other rods for holding the head and frame in proper relation. magnets mounted on said rods one above the other and adapted to be withdrawn when the rods are detached from the frame, spacers between the magnets, and means for clamping the magnets and spacers in place.

11. A regulating-magnet for an alternatingcurrent arc-1amp, comprising two pairs of differentially-aoting coils in series and shunt relation to the are respectively, an H-shaped laminated core having its limbs entering the several coils, and laminated yokes connecting the coils at their outer ends.

12. A reactance for an alternating-current arc-lamp, supported on the lamp-frame by a plurality of cushions engaging it at a number of distributed points of small area.

13. In an alternating-current arc-lamp, the combination of a reactance having an air-gap core, a frame, supports secured thereto and arranged to extend through the core in such a manner that the core is free to move, and springs situated under the core and arranged to absorb the vibration.

14. In an alternating-current arc-lamp, the combination of a frame, a carbon-carrier, a reactance which surrounds the carbon-carrier and is provided with an air-gap core, springs for supporting and absorbing the vibration of the core, and fixed guides loosely engaging the core on which itis free to vibrate.

15. In an alternating-current arc-lamp, the combination of the frame, a reactance having an air-gap core, screws which pass through the core into thelamp-frame, and springs surrounding the screws between their heads and the lower portion of the core for absorbing the vibration of the reactance.

In witness whereof I have hereunto set my hand this 25th day of February, 1899.

RICHARD FLEMING.

Witnesses:

ALEC F. MACDONALD, DUGALD MoKILLoP. 

